1. Field of the Invention
The present invention relates to a common connector for memory cards, in particular to a common connector for memory cards and a switching arbitration method for the shared Pins of the connector.
2. Description of Related Art
Currently, portable memory devices mainly comprises of magnetic memory products, magnetic disks or optical disks utilizing optical storage technologies, and flash memory devices utilizing semiconductor storage technologies. In above 3 categories, flash memory products are the most popular in the industry, which are often called memory cards or mini-cards such as PCMCIA ATA Flash Card (PC card), CompactFlash Card (CF Card), Smart Media Card (SM Card), Multimedia Card (MMC), Memory Stick Card (MS Card), and Secure Digital Card (SD Card), etc. This type of flash memory cards is far better than the other types mentioned above in portability, power consumption, data storage, data transfer rate, rewriting, shockproof and moisture-proof features. By now, it has been widely used in consumer electronic products such as DSCs, DVRs, and PDAs as well as in new portable devices such as Smart Phones, Mobile PCs, Mobile Phones, MP3 Players, and GPS products.
Besides said benefits and price advantage of portable memory devices, the main influential factor that effect the market is the acceptance of consumers, i.e., the sizes of connectors and the connection ability between memory cards and connectors have great influence on the popularization of the products in the market. In fact, portable memory devices are originally used in computer systems (desktop or notebook) or in consumer electronic products such as DSCs and PDAs. However, in order to comply with standards of different types of memory cards in the current market, and to connect usual computer systems and other connectors, connectors supporting a single memory card are already available, and even those supporting a multiple of different types of memory cards have appeared.
Particularly, the connectors supporting a multiple of different types of memory cards, sets of Pins for specific memory cards are devised in sequence on the top board and the bottom board, and the sets of Pins are welded respectively according to supported interface jack and memory cards can only be inserted and fixed in the direction of the Pins are devised. Therefore, card detection switches to detect the features of memory card inserted and write protection switches have to be devised near the insertion end, which will enlarge the size of the connector. However, large connectors are not suitable for the trend of ‘light in weight’, ‘thin in thickness’, and ‘small in size’, which is the main factor of the portable memory devices being introduced into the market.
Moreover, because that corresponding and exclusive Pins are used in traditional connectors and only detection and arbitration for single interface signal are required, the circuit and control unit of traditional connectors are relatively simple. In other words, the insufficiency in flexibility in such a connector is not a vital problem. Also, in such a design, due to the configuration of Pins, card detection switches, and write protection switches, the size/volume of the connector supporting a multiple of types of memory cards is relatively large.